Well swab



May 21, 1940- B. E. Fmr-misml 2,201,451

4 Sheets-Sheet 2 B. E. 4FARP-@ISH WELL SWAB Filed Feb. 27, 1957 May 2l,1940.

May 2l, 1940. B. E. PARRISH WELL swAB Filed Feb. 27, 1957 I 4Sheets-Sheet 3 B. E. PARRlsH WELL SWAB May 21, 1940.

Filed Feb. 2'7, 1957 4 Sheets-Sheet 4 Y nur 0km ii.

Patented May 2l, 1940 UNITED STATES PATENT OFFICE WELL swan Benjamin E,ran-a1., n.11, rex. .Application February 21, 1237, semi No. 128,047 y21 Claims.

This invention relates to new and useful improvements in well swabs.

'I'his application is illed as an improvement on the well swab disclosedin my co-pending application, filed July 22, 1935, Serial Number 32,561.

Qne object of the invention is to provide an improved swab having all ofthe advantages of the swab' disclosed in my co-pending application andwhich is particularly adapted for use in oil wells, being constructed soas to descend rapidly in the well uid, whereby the swab may-be run in aminimum amount of time.`

An important object of the invention is to provide an improved swabwherein the packing element is constructed in sections arranged to bedisplaced out of horizontal alinement with each other so that the iiuidmay by-pass said element, the displacement being automatic on thedownstroke; said sections being mounted on a supporting mandrel, wherebysaid mandrel not only serves as a support for the packing element butalso acts as a guideduring the displacement of the sections, therebyeliminating an auxiliary -guide means and making for a more simple andan improved well swab having a split elastic packing element with onehalf of said element arranged to undergo vertical movement with relationto the other half, and improved means for limiting the distortion of thepacking whereby distortion of the packing element beyond its elasticlimits is prevented.

Still another object of the invention is to provide an improved swabwherein the packing element is constructed in units, the parts of thevarious units being interchangeable with each other, wherebymanufacturing costs are minimized and assembly of the device greatlysimplified.

A still further object of the invention is to provide an improved swabwherein all valves, balls, seats, etc., are eliminated and wherein thesize of the iiuid by-pass may be readily adjusted to control the speedat which the swab descends through iiuid in the well casing or tubing;the assembly being simple in. manufacture and air--v ranged to beattached to any suitable lowering rod, cable or device.

A construction designed to carry out the invention will be hereinafterdescribed together with other features of the invention.

The invention will be more readily understood from a reading of thefollowing specification and by reference jto the accompanying drawings,in which an example of the invention is shown, and wherein: y

Figure 1 is an elevation of a swabconstructed in accordance with theinvention, and showing the packing element in its packing position,

Figure 2 is a view similar to Figure 1 and showing the sections ofthepacking element if placed vertically `from each other,

at right angle Figure 3 is an elevation taken to Figure 1,

Figure 4 is an elevation taken at right angle 20 to Figure 2,

Figure 5 is a transverse, vertical sectional view of the swab, taken onthe line 5-5 of Figure 3 and showing the mandrel in elevation,

Figure 6 is a view similar to Figure 5 taken on the line 6-6 of Figure4,

Figure 7 is an isometric view ofthe supporting mandrel,

Figure 8 is a perspective view showing the elements of each section. 0runit of the packing member separated from each other,

Figure 9 is a horizontal, cross-sectional view, taken on the line 9 9 ofFigure l,

Figure 10 is a horizontal, cross-sectional view, taken on the lineID-II) of Figure 1, and

Figure l1 is a horizontal, cross-sectional view, vtaken on the lineII-II of Figure 2.

In the drawings, the numeral I0 designates a mandrel which is preferablymade of a solid piece of metal, or other suitable material. The mandrelis substantially cylindrical in cross-sections and has its upper endprovided with screw threads II, whereby a box I2 may be screwed thereon.The box is provided with an upwardly extending integral nipple I3, whichis of s'uch size as to receive the standard threaded box (not shown) atthe lower end of the usual sucker rod, whereby the mandrel may bereadily connected to said rod and lowered into the well casing A. It ispointed out that the box I2 may be readily removed and a similar boxhaving a nipple of a diil'erent diameter may be substituted therefor,whereby the mandrel could be lowered by means of a pipe or cable insteadof a sucker rod. With such arrangement specially designed couplings areunnecessary and the mandrel may be connected with any of the usuallowering devices.

The lower end of the mandrel Il) is provided with screw thread i4,whereby a plug i5 may be attached to the lower end of the mandrel. Theplug preferably has its lower end rounded so that as the mandrel islowered into the iluid, such lowering is facilitated by this roundedportion.

Mounted on the mandrel I0 is a flexible or elastic packing element it.The packing element is constructed of two halves or units B and C whichare semi-circular in cross-section and are arranged to fit around themandrel as clearly shown in Figure 9. Both units of the packing elementare exactly alike so that when they are positioned in horizontalalinement with each other they form an annular packing element. The unitB is slideable vertically throughout the length of the mandrel. Ill,while the unit C is mounted in a ilxed position at the lower end of saidmandrel as will be explained. With this arrangement the unit B may bedisplaced vertically out oi hori- 'zontal alinement with the other unitC.

Since each unit is exactly like the other, a description of one willsufiice. Each unit includes an elastic or resilient packing member I1which is substantially semi-circular in cross-section and which has itsouter surface tapered inwardly at its upper and lower ends, as isclearly shown in Figure 8. The upper end of the packing member isadapted to fit within the recess i8 of a thimble i9. 'I'he thimble issubstantially semi-circular in cross-section and is arranged to snuglyfit the outer surface of the cylindrical mandrel I0. The inner wall ofthe thimble i9 is extendeddownwardly to form a projecting skirt 2liwhich extends contiguous to the inner wall of the packing member whensaid member is in position within the thimble. For fastening the upperend of the packing member within the recess I8 of said thimble, thepacking element is formed with a radial opening which is in alinementwith an opening 2| which is formed in the inner wall of the thimble(Figure 5). The outer wall of the thimble is formed with a reducedopening 22, the inner end ofwhich is enlarged to the diameter of theopenings and 2|, whereby an internal annular shoulder 23 is formed inthe outer wall of said thimble. It is noted that the openings 2|, I1 and22 are in alinement with each other. After the upper end of the packingmember l1 has been inserted into recess I8 of the thimble I9 and beforethe unit is placed around the mandrel, as will be explained, a pin 24 isinserted into the opening from the inside of the thimble. This pin has adiameter of such size as to snugly ilt in the openings 2| and I1' andinto the enlarged portion of the opening 22. The extreme outer end ofthe pin is reduced as shown at 24' so as to tlt within the reducedopening 22 in the outer wall of the thimble. The off-set or shoulderformed on the pin 24 abuts the internal annular shoulder 23 in the outerwall of the skirt, whereby outward movement of the pin is prevented.Whenthe unit is mounted on the mandrel I0, the inner end of the pinengages the outer surface of said mandrel, whereby inward displacementof the pin is prevented. When it is desired to remove the pin, it ismerely necessary to remove the unit from the mandrel and push the pininwardly out of the opening. With such arrangement a most simple andeffective retaining means is provided for holding the packing member inplace within the thimble i9.

The lower end ot the packing member i1 is inserted within the recess 25of a thimble 2i, which is similar in construction to the upper thimbleI9. The lower end of the packing member is retained within the lowerthimble by a pin 21, similar to the pin 24. It is noted that when thepacking member is secured between the thimbles il and 26, the inner. endof the skirt 2li of the upper thimble and the inner end of the lowerskirt 2l of the thimble 26 are spaced from each other. This position isclearly shown in Figure 5, and occurs when the packing member l1 is inits normal or undistorted position.

For slideably mounting the unit B on the mandrel I0 said mandrel isprovided with a pair of diametrically opposite grooves or keyways 28which extend vertically throughout the length of the mandrel. Eachthimble I9 and 26 is provided with inwardly projecting ribs or keys Ilwhich are located at the inner surface thereof. The ribs or keys areadapted to slide within the grooves or recesses 29 in the mandrel andobviously, prevent displacement of the unit from said mandrel. Inmounting the unit on said mandrel it is only necessary to remove theplug i5 at the lower end thereof, and to slide the unit upwardly on themandrel, whereby the keys 30 engage the groove. The plug is thenreturned to the lower end of the mandrel and it will be seen that theunit B is confined to a vertical movement between said plug and thesocket I2 at the upper end of the mandrel.

The unit C is constructed exactly as is the unit B and is mounted on themandrel il in a similar manner. However, the inwardly projecting ribs orkeys 30 of the thimbles of the unit C engage in diametrically oppositeslots or keyways 3|. The length of the keyways 3| is less than thelength of the lzeyways 28, being substantially the vertical length ofthe unit C. Thus the grooves or keyways 3| extend from the lower end ofthe mandrel In to a ,point opposite the upper end of the unit C. It isnoted that the keyways 3l extend contiguous to the keyways V29 andtherefore the lower end of the latter are combined with the former toform a comparatively wide groove at the lower end of the mandrel. Sincethe keyways or grooves 3| terminate at the upper end of the unit C itwill be seen that when said unit is mounted on the mandrel, theuppermost thimble i9 of the unit will abut the end of the groove 3|. Itwill be held in this position by the engagement of the plug i5 with itslower end, whereby the unit C is mounted in a fixed position incapableof movement with relation to the mandrel, on said mandrel. Since thegrooves 29 within ,which the unit B is slideable extend throughout thelength of the mandrel and it will be evident that this unit may slidevertically with relation to the unit C which is attached in a fixedposition on said mandrel.

In operation, the assembly is secured to a single pipe, sucker rod orother lowering device and lowered into the well casing A with the partsin the position shown in Figures 1, 3 and 5. As soon as the assemblystrikes the fluid within the well casing, the fluid pressure willimmediately raise the unit B of the packing element on the mandrel i0,the vertical keys 30 on the thimbles of said unit sliding upwardly inthe diametrically opposite grooves or keyways 29. The mandrel is ofsufficient length so as to permit the unit B to move upwardly to theposition shown in Figures 2, 4 and 6, with the lower end of the unit Bopposite the upper end ofthe unit C.

'I'he thimbles I9 and 26 oi.' both units B and C are inclined inwardlytoward their outer end and due to this inclination, it will be seen thatan enlarged space D, as indicated in Figure 4, is provided between theunits B and C when the former is in its raised position. This spacepermits the fluid to flow from beneath the assembly upwardly thereby andis substantially equal to the crosssectional area oi.' the casing A,whereby there isv prac'tically no resistance to the downward passage ofthe assembly in the well casing. The enlarged by-pass permits theassembly to be lowered rapidly and each rim may be madein a minimumlength oi time. It is obvious that the displacement of the units of thepacking assembly out of horizontal alinement with each other acts as avalve to permit by-passlng of the fluid on the downstroke of the device.

When the assembly has reached its lowermost position and the raisingoperation has begun, the uid pressure above the assembly willimmediately act upon the raised unit B ioA lower the same. This unitwill of course, immediately move downwardly on the mandrel until thelower end of its thimble 2l rests upon the plug I5 screwed on to thelower end of said mandrel. In this position, the unit B is opposite thestationary or fixed unit C and the fluid will then act upon both umts toforce the thimbles I9 thereof downwardly toward the lower thimble 26,whereby the resilient or elastic packing members I'I which are confinedbetween said thimbles, are expanded into engagement with the inner wallof the well casing A. The upper thimble I9 will move downwardly untilthe inner edge of the skirts which project downwardly therefrom, strikethe inner edge of the upwardly projecting skirts 28 on the lower thimble26. When this occurs. further distortion of the packing member II isprevented. Therefore, it will be seen that the extended skirts providedon the thimbles provide a positive means for preventing a distortion ofthe packing member I'I beyond the elastic limits of said members. Theinner faces of the thimbles I9 and 26 of both units are machined so thatwhen the two units are in horizontal alinement, a ground joint whichprevents leakage is formed. Continued upward movement of the assemblyafter the packing members l1 have moved into engagement with the wellcasing A, will lift the iiuid above the packing element and at the sametime the well of the casing will be swabbed.

It is pointed out that when the swab is being lowered in the `wellcasing and the unit B is in its raised position (Figure 4), there is apossibility that a stone, rock or other extraneous matter may becomelodged in the space D between the lower thimble 26 of the unit B and theupper thimble I9 of the unit C. Due to the inclination of the outer wallof the thimble, it will be seen that should this occur, a downwardmovement of the upper unit C will provide a shearing or cutting actionas the lower thimble of the unit C slides downwardly with relation tothe upper thimble 26 and the unit C. This shearing action would removeany extraneous matter which might become lodged between the units' andtherefore any danger of such extraneous matter preventing the units frommoving back into horizontal alinement upon the beginning of the upstrokeis eliminated.

From the above, it will be seen that a swab wherein the packing elementis utilized as a valve is provided. 'Ihe structure is such that theentire assembly is made of a minimum number of parts and may be quicklyand easily attached to or detached from the mandrel. The removal of theplug I5 from the lower end 'of said mandrel will permit both the units Band C to be slid from the lower end of said mandrel. After the units areremoved, it is only necessary to knock out the pins 24 and 21 toentirely disassemble each unit. This makes for easy replacement of thepacking member I'I.

Manufacturing is simplied and cost greatly reduced by formingdiametrically opposite vertical grooves or keyways in the mandrel. Thesegrooves not only serve as a positive guide means for the movement of theunit B but also provide a positive means for holding the unit on themandrel. By so utilizing the grooves, it is not necessary to employextraneous guide means for the unit B: The parts of each unit areinterchangeable with the parts of all the other units and thus all thethimbles present in both units may be used on either one and either atthe upper or lower end of each. 'I'he packing members II are exactlyalike and can be mounted in either the unit B or the unit C. Theinterchangeability oi' the parts makes for easy assembling of the deviceas well as materially reducing the cost of manufacture. It is againnoted that the by-pass D is of such size as to eliminate any greatresistance in the downward travel of the assembly which makes for rapidlowering oi' the device in the well uid present in the well casing A.The provision of the box I2 having the nipple I3, an integral partthereof, eliminates the necessity of providing special coupling, wherebythe assembly may be lowered by any suitable lowering device now on' theopen market.

What I claim and desire to secure Patent is:

1. A well swab including, a mandrel having vertical grooves therein, apacking assembly mounted on the mandrel and including a pair of unitswhich are arranged to be displaced out oi.' horizontal alinement witheach other to permit the well fluid to freely by-pass the assembly onthe downstroke of the swab, and means on each unit for engaging thegrooves of the mandrel for retaining said units on said mandrel.

2. A well swab including, a mandrel, a packing assembly mounted on themandrel, said assembly including a stationary unit and a movable unit,said movable unit being arranged to be displaced vertically out ofAhorizontal alinement with the stationary unit, and lco-acting groovesand ribs on the mandrel and units for retaining the units in position onsaid mandrel.

3. A well swab including, a mandrel, a packing assembly mounted on themandrel, said assembly including a stationary unit and a movable unit,said movable unit being arranged to be displaced vertically out ofhorizontal alinement with the stationary unit, and co-acting grooves andribs on the mandrel and units for retaining the units in position onsaid mandrel, and for guiding the movable unit in its vertical movement.

4. A well swab including, a mandrel, a packing assembly carried by themandrel and comprising a pair of units, the mandrel and units havingcoacting grooves and ribs for retaining the units on said mandrel, andan elastic packing element constructed in two sections, one of which ismounted in one of the units which is stationary on the mandrel, theother section being carried by the other unit which is movablevertically on the mandrel, whereby the latter packing section may bedisplaced vertically with relation by Letters to the other section toprovide an enlarged space to permit the well fluid to by-pass thepacking element freely on the downstrokeof the swab.

5. A well swab including, a mandrel, a packing assembly mounted on themandrel, said assembly including a stationary unit and a movable unit,said movable unit being arranged to be displaced vertically out ofhorizontal alinement with the stationary unit to permit the well iluidto freely by-pass the assembly on the downstroke of the swab, themovable unit being arranged to move back into horizontal alinement withthe stationary member and to be distorted into packing position withsaid stationary member upon the upstroke of the swab, and co-actinggrooves and ribs on the mandrel and units for retaining the units inplace on said mandreL l 6. A well swab including, a mandrel, a packingassembly mounted on the mandrel, said assembly including a stationaryunit and a movable unit, said movable unit being arranged to bedisplaced vertically out oi.' horizontal alinement with the stationaryunit to permit the well fluid to freely by-pass the assembly on thedownstroke of the swab, the movable unit being arranged to move backinto horizontal alinement with the stationary member and to be distortedinto packing position with said stationary member upon the upstroke ofthe swab, and co-acting grooves and ribs on the mandrel and units forretaining the units in place on said mandrel, and for guiding themovable unit in its movement.

'1. A well swab including, a mandrel having vertical grooves therein, apacking assembly mounted on the mandrel and including a pair of unitswhich are arranged to be displaced out of horizontal alinement with eachother to permit the well uid to freely by-pass the assembly on thedownstroke of the swab, each unit comprising an elastic packing membersubstantially semicircular in cross-section so as to t around themandrel, confining elements at each end of the member for holding saidmember therebetween, and means on said elements for engaging the groovesof the mandrel for retaining the units on said mandrel.

8. A well swab including, a mandrel having vertical grooves therein, apacking assembly mounted on the mandrel and including a pair of unitswhich are arranged to be displaced out of horizontal alinement with eachother to permit the iluid to freely by-pass the assembly on thedownstroke of the swab, each unit comprising anA elastic packing membersubstantially semi-circular in cross-section so as to t around themandrel, conilning elements at each end of the member for holding saidmember therebetween, means on said elements for engaging the grooves ofthe mandrel and for guiding the movable unit in its movement, and meansfor limiting the distortion of the packing members.

9. A well swab including, a single longitudinal supporting member, anelongate packing assembly mounted on the member and including astationary unit and a movable unit, said movable unit being arranged tobe displaced longitudinally out of registration with the stationaryunit, and longitudinal means on the single member co-acting with thestationary unit to hold said unit on said member, said means alsoco-acting with the movable unit for retaining said unit on the memberand for guiding the same in its longitudinal movement.

1G. As a sub-combination in a well swab, a packing assembly including, agrooved support,

a split sealing element, and split top and bottom caps therefor, saidcaps having vertical ribs for engaging the grooved support to retainsaid assembly on said support.

1l. As a sub-combination in a well swab, a packing assembly including,-a grooved support, a split sealing element, and split top and bottomcaps therefor, said caps having means for engaging the grooved supportto retain said assembly on said support.

l2. As a sub-combination in a well swab, a sealing assembly including, arecessed support, a pair of upper confining members each semicircular incross-section, a pair of lower confining members of semi-circularcross-section, and a pair of elastic packing elements coniined betweenthe upper and lower members, said packing elements also beingsemi-circular in cross-section, each confining member having verticalribs extending substantially throughout its length at its longitudinalextremities and arranged to coact with a recessed support to retain theassembly on said support.

13. As a sub-combination in a well swab, a single supporting mandrelhaving diametrically opposed grooves extending substantially throughoutits length, each groove having one end enlarged in transverse widthwhereby the enlarged portion is substantially twice the width of theremainder of the groove.

14. A well swab including, a mandrel, a swab element surrounding themandrel and including a plurality of registering sections having elasticdeformable members arranged to be fdeformed by the liquid lifted when inregistration with each other, one of said sections being immovable onsaid mandrel and the other section being slidable longitudinally on saidmandrel from the first section to provide a free by-pass for liquidbetween said sections, whereby the swab may be quickly lowered in a bodyof liquid in a well, longitudinal guide means formed on the periphery ofsaid mandrel, and means on the movable section of the element co-actingwith said guide means to retain said movable section in registeringposition and for guiding said section into registration with thestationary section.

15. A well swab including, an elongate supporting member havingabutments remotely spaced apart, a packing element mounted on thesupporting member and including two sections which in one position arein registry and, one of which is stationary on said member and the otherof which is slidable longitudinally between the abutments thereof, thestationary section engaging one of the abutments of the member, and theslidable section engaging the other abutment, whereby its displacementfrom the other section is limited, and interlocking means between thesupporting member and the slidable section of the packing element forretaining said section thereon and against rotation.

16. A well swab including, a mandrel, a swab element surrounding themandrel and having a displaceable section movable longitudinallyapproximately its entire length on the mandrel, and means formed on theperiphery of said mandrel for guiding the section longitudinallythereof.

17. A well swab including, a single longitudinal supporting member, apacking assembly mounted on the member and including a pair of units,one of which is arranged to be displaced out of horizontal alinementwith the other, the supporting member having longitudinal guide means ofgreater length than either of said units formed on the periphery of themember, and means on the movable unit for engaging said guide means,whereby said unit is held in longitudinal alinement when displaced.

18. A well swab including a single supporting mandrel, a packingassembly carried by said mandrel,.and including a pair of units, one ofwhich is slidable longitudinally of the mandrel relative to the otherunit of said pair, and means to mount the slidable unit on the mandrel,thereby to derive sole support from the latter, co-mprising guide meansformed on the periphery of the mandrel, and complementary guide means onthe slidable unit engaging the guide means of said mandrel to hold theslidable unit against rotation.

19. A well'swab in accordance with claim 18, wherein the guide means onthe mandrel consists of a. pair of grooves extending longitudinally ofthe mandrel and located on opposite sides thereof, to form projections,and wherein the complementary guide means have recesses receiving theprojections and portions extending into the grooves.

20. A Well swab including a. single supporting rod, a packing assemblycarried by said rod and including a pair of units one of which ismovable longitudinally away from the other, said rod having an irregularcross-section, which constitutes its periphery, so as to hold saidmovable unit against rotation while permitting longitudinal movementthereof, and means carried by the movable unit and engaging theperiphery of the rod to mount' the movable unit on the rod.

21. A well swab including a single supporting rod, a packing assemblyincluding a pair of units Carried by said rod, one of which is slidablelongitudinally of the rod relative to the other unit of said pair ofunits, and means to mount the slidable unit onthe rod thereby to derivesole support therefrom, comprising complementary interlocking meansbetween the rod and the-

